Alcohol ethoxylates ASTM standard

ASTM Test Method D 4252-89 Standard Test Methods for Chemical Analysis of Alcohol Ethoxylates and Alkylphenol Ethoxylates. American Society for Testing and Materials, Philadelphia, USA. 

This determination is best made by HPLC or CE, as described in Chapters 7 and 11. Under the proper conditions, a single peak is obtained for nonionic impurities. The standard extraction method for unsulfated material in alcohol sulfates (ASTM D 1570) is not appropriate for ethoxysulfates because the solubility characteristics of ethoxylated fatty alcohols differ from those of fatty alcohols. The products with higher degrees of ethoxylation will not be completely extracted and emulsion formation may altogether prevent extraction. 

The complete analysis of alcohol sulfates is described in the Standard Methods of the International Organization of Standards (ISO) [200] and of the American Society for Testing and Materials (ASTM) [201]. These methods describe the analysis of inorganic sulfate content, chloride content, unsulfated matter, and water as well as other analytical values. Other ISO standards describe the analysis of sodium secondary alkyl sulfates [202], determination of pH [203], determination of water content [204,205], chlorides [206], total active matter in sul fated ethoxylated alcohols and alkylphenols [207], mean relative molecular mass in sulfated ethoxylated alcohols and alkylphenols [208], sulfate content... 

These materials are readily determined by two-phase titration (ISO 2271) or potentiometric titration with benzethonium chloride. On acid hydrolysis they yield the corresponding alcohol, a sulphate ion and a hydrogen ion, and this affords three additional approaches—determination of the increase in acidity, of the amount of fatty alcohol or ethoxylated alcohol liberated, and of the sulphate ion. The experimental procedure may be varied within limits for example ISO 2870 [5] and ASTM D 1570-89 [6] differ with respect to the identity of the acid used, duration of boiling, choice of indicator and other details. The following procedures are similar to both of those standard methods. The choice of indicator is immaterial for these particular compounds, but is of crucial importance in some other cases. 

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